By Nikhil Swaminathan Hey, candidates. Want to win an election? Simple. Just appear competent—even if you're not. A new report confirms what may be some politically inclined people's worst nightmare: looks matter. Princeton University researchers asked student volunteers which of two candidates in gubernatorial races appeared more competent. Much to the scientists' surprise, their picks turned out to be the voters' choices. Study participants were shown photos of the winners and losers in 89 political races that took place between 1996 and 2002. The subjects were given either 100 milliseconds, 250 milliseconds or an unlimited amount of time to choose candidate that they perceived as more competent; in all cases they were instructed to go with their gut. The students' selections were also the election winners in 64 percent of the cases. In a second trial, the volunteers were given either 250 milliseconds or two seconds to mull over their decisions. When given longer time to ponder, the students' individual responses became 5 to 7 percent less predictive, but their overall success rate bumped up to an average 69.1 percent. In a third experiment, which involved yet-to-be-held gubernatorial races, the group did similarly well (68.6 percent) when asked to go with their first impulse, but take as much time as they needed to answer, allowing them to deliberate. "All of the action goes on in the first 250 milliseconds of exposure, and then there's not much going on," says Alexander Todorov, an assistant professor of psychology and co-author of the study, which appeared in Proceedings of National Academy of Sciences USA, noting that these 250-millisecond trials yielded the greatest predictive success. "If they deliberate, they get slightly worse. [Though], they are still above chance in picking the winner." © 1996-2007 Scientific American, Inc

Keyword: Attention; Emotions
Link ID: 10882 - Posted: 06.24.2010

Peter F. MacNeilage A dog earns its reputation as best friend in part because it wags its tail in joy at the sight of its owner. But as a team of Italian researchers led by the University of Bari's Antonio Quaranta reveal in a recent article in Current Biology ("Asymmetric tail-wagging responses by dogs to different emotive stimuli," 20 March 2007), the wag of a dog's tail tells a much larger story. Quaranta and colleagues, examining closely the lesser-remarked fact that dogs wag their tails not just in pleasure but also when they are uneasy with an animal they are encountering, found a dog wags its tails differently in these two types of encounters: it wags the tail more to the right while greeting its owner but more to the left when meeting an unfamiliar dominant dog. Because the brain's control of the body is crossed, a bias in one direction means more activation of the brain hemisphere on the opposite side. Thus a dog's tail reveals which half of its brain is responding. This finding ties into a fascinating line of research regarding hemispheric specialization, evolution, specialized tasks versus routine, and how much like monkeys -- or dogs -- we humans might be. This study is important partly because it subjected a single population to a single experimental paradigm. This provides a more powerful demonstration than if the findings came from different paradigms applied to different subject groups; it compares apples to apples. And these tail-wagging biases fit into a general evolutionary perspective -- a sort of division of labor between right and left brain -- that involves not just mammals but also other major vertebrate groups, including fish, reptiles and birds. © 1996-2007 Scientific American, Inc.

Keyword: Animal Communication; Laterality
Link ID: 10881 - Posted: 06.24.2010

By Elie Dolgin Many more genes separate humans from chimpanzees than scientists believed. A new study shows that what sets us apart from our closest primate cousin is the accelerated rate at which we acquire new genes and ditch unnecessary ones. It's often said that there's only 1% to 2% difference between the genomes of chimps and humans, two species that had their most recent common ancestor about 5 million years ago. But that percentage refers to the nucleotide differences in shared genes. Evolution can do more than just tinker with gene sequences; the number of copies of a gene can also vary from one species to the next, even when the gene itself stays the same. Sometimes genes are gained, and sometimes they are lost. Quantifying this turnover has been difficult, however, because it requires the complete genome sequences of many species. Now, with several mammals sequenced and a suite of new statistical methods available, Matthew Hahn and colleagues at Indiana University, Bloomington, have taken a closer look. They measured how quickly genes were duplicated or lost across six mammalian genomes. By looking at about 120,000 genes in 10,000 gene families, they discovered that gene turnover was faster in primates than in dogs or in rodents, and even faster in humans, who swapped genes 1.6 times faster than monkeys and 2.8 times quicker than nonprimates. Thanks to this rapid change, 6.4% of the 22,000-odd human genes aren't present in chimps, making the gap between the two suddenly seem much wider.

Keyword: Evolution; Genes & Behavior
Link ID: 10880 - Posted: 10.24.2007

WASHINGTON - Having more years of formal education delays the memory loss linked to Alzheimer's disease, but once the condition begins to take hold, better-educated people decline more rapidly, researchers said on Monday. Their study, published in the journal Neurology, tracked memory loss in a group of elderly people from New York City's Bronx borough before they were diagnosed with Alzheimer's or another form of old-age dementia. Every year of education delayed the accelerated memory decline that precedes dementia by about 2-1/2 months, according to the researchers at Yeshiva University's Albert Einstein College of Medicine in New York. But once this memory loss began, the rate of decline unfolded 4 percent more quickly for each additional year of education, the researchers said. Someone with 16 years of schooling might experience memory decline 50 percent more quickly than another person with just four years education, based on the findings. Alzheimer's disease is a degenerative brain malady that is the most common form of dementia among the elderly. "An elderly person who starts to see memory loss might well deteriorate fairly rapidly, particularly if he or she has a high education or high IQ," Charles Hall, a professor of epidemiology at Albert Einstein College of Medicine who led the study, said in a telephone interview. Exercise your mind © 2007 MSNBC.com © 2007 Microsoft

Keyword: Alzheimers; Learning & Memory
Link ID: 10879 - Posted: 06.24.2010

Our genes and not just our upbringing may play a key role in our food likes and dislikes, UK researchers believe. Experts from Kings College London compared the eating habits of thousands of pairs of twins. Identical twins were far more likely to share the same dietary patterns - like a penchant for coffee and garlic - suggesting tastes may be inherited. A health psychologist said this meant childhood food foibles might be harder to put right than previously thought. Identical twins have exactly the same genetic make-up as each other, so scientists, by comparing them to non-identical twins, can work out the likelihood that their characteristics are due to "nature" or "nurture". The Kings College researchers looked at a total of more than 3,000 female twins aged between 18 and 79, working out their broad preferences using five different dietary "groups". These included diets heavy in fruit and vegetables, alcohol, fried meat and potatoes, and low-fat products or low in meat, fish and poultry. Their results, published in the journal Twin Research and Human Genetics, suggested that between 41% and 48% of a person's leaning towards one of the food groups was influenced by genetics. The strongest link between individual liking and genes involved a taste for garlic and coffee. Professor Tim Spector, who led the research, said: "For so long we have assumed that our upbringing and social environment determine what we like to eat. This has blown that theory out of the water - more often than not, our genetic make-up influences our dietary patterns." (C)BBC

Keyword: Obesity; Genes & Behavior
Link ID: 10878 - Posted: 10.23.2007

By Edyta Zielinska Sex differences in addictive behavior, long linked to female hormones, may also be driven by genetic factors, according to a new study published online in Nature Neuroscience. "I think [the study is] very cool," said Ronald See at the Medical University of South Carolina, who was not involved in this research. The investigators have established a simple method for teasing out sex and hormonal differences that can now be applied to behavioral tests, he said. A now-classic study that compared male and female responses to cocaine showed that females were more sensitive to the drug's reward effects during the estrus phase of their menstrual cycle, establishing the theory that hormone levels influence addictive behavior. But the contribution of sex chromosomes was not previously examined because there was no technique for separating hormonal factors from genetic ones. Jane Taylor of Yale University and colleagues identified a naturally occurring mutant mouse in which males lacked a gene on the Y chromosome called SRY that is responsible for the formation of testes. These mutants, while chromosomally male, did not develop testes. The researchers then inserted the SRY gene onto an autosomal chromosome of a mutant male -- which developed normal testes -- and crossed that animal with a normal female. The resulting strain consisted of four phenotypes: genetic males with testes; genetic males with ovaries; genetic females with ovaries; and genetic females with testes. © 1986-2007 The Scientist

Keyword: Sexual Behavior; Drug Abuse
Link ID: 10877 - Posted: 06.24.2010

By INGFEI CHEN On a sun-drenched morning this month, a small, black, bushy-haired dog trotted out from the animal care center at Stanford. The Belgian schipperke, Bear, soon veered off to lift a hind leg over a shrub. He was, clearly, oblivious to the gravitas of the day. Bear had spent nearly seven years in the underground kennels as part of a colony of narcoleptic dogs studied by Dr. Emmanuel Mignot, director of the Stanford Center for Narcolepsy. Dr. Mignot had just signed papers to adopt the dog, the last of the colony. Bear’s freedom ended 30 years of investigations that led to the discovery of the importance of a neurochemical called hypocretin in human and animal narcolepsy, and in normal sleep. Bear will now be a pet. And Dr. Mignot has turned to less huggable research subjects, like wet, cold-blooded and, unexpectedly, less cooperative zebrafish. Investigators now understand that narcolepsy arises from a deficiency of the brain cells that make hypocretin, similar to the way that Parkinson’s is caused by the loss of dopamine-producing neurons. Copyright 2007 The New York Times Company

Keyword: Narcolepsy
Link ID: 10876 - Posted: 06.24.2010

By CARL ZIMMER Last month, a bird known as a bar-tailed godwit took flight from Alaska and headed south. A day later, it was still flapping its way over the Pacific. An airplane pilot would have a hard time staying awake after 24 hours of flight (the Federal Aviation Administration allows pilots to fly just eight hours in a row). But the godwit kept flying for an additional week. After eight days and 7,200 miles, it landed in New Zealand, setting a record for nonstop flight. “If they spend so many hours flying,” said Ruth M. Benca of the University of Wisconsin, “where do they find the time to sleep?” Bird sleep is so mysterious that scientists are considering several answers, all intriguing. The godwit may have managed to stay awake for the entire journey. Or it may have been able to sleep while flying. Or, as Dr. Benca and other scientists suspect, its brain may have been in a bizarre state of semilimbo that they do not understand. Bird brains produce patterns of electrical activity that look strikingly like human brains during sleep, a remarkable similarity considering that birds and their brains have been on a separate evolutionary course from mammals for 300 million years. But similarities reach just so far. The amount of sleep birds need can change drastically through the year. Birds may be able to put parts of their brains to sleep while keeping others awake. They may be able to adjust sleep in the course of minutes, even seconds. By figuring out the mysteries of bird sleep, scientists hope to understand some universal rules of sleep. Copyright 2007 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 10875 - Posted: 06.24.2010

By STEPHANIE SAUL Your dreams miss you. Or so says a television commercial for Rozerem, the sleeping pill. In the commercial, the dreams involve Abraham Lincoln, a beaver and a deep-sea diver. Not the stuff most dreams are made of. But if the unusual pitch makes you want to try Rozerem, consider that it costs about $3.50 a pill; gets you to sleep 7 to 16 minutes faster than a placebo, or fake pill; and increases total sleep time 11 to 19 minutes, according to an analysis last year. If those numbers send you out to buy another brand, consider this, as well: Sleeping pills in general do not greatly improve sleep for the average person. American consumers spend $4.5 billion a year for sleep medications. Their popularity may lie in a mystery that confounds researchers. Many people who take them think they work far better than laboratory measurements show they do. An analysis of sleeping pill studies found that when people were monitored in the lab, newer drugs like Ambien, Lunesta and Sonata worked better than fake pills. But the results were not overwhelming, said the analysis, which was published this year and financed by the National Institutes of Health. Copyright 2007 The New York Times Company

Keyword: Sleep
Link ID: 10874 - Posted: 10.23.2007

By BENEDICT CAREY The task looks as simple as a “Sesame Street” exercise. Study pairs of Easter eggs on a computer screen and memorize how the computer has arranged them: the aqua egg over the rainbow one, the paisley over the coral one — and there are just six eggs in all. Most people can study these pairs for about 20 minutes and ace a test on them, even a day later. But they’re much less accurate in choosing between two eggs that have not been directly compared: Aqua trumped rainbow but does that mean it trumps paisley? It’s hazy. It’s hazy, that is, until you sleep on it. In a study published in May, researchers at Harvard and McGill Universities reported that participants who slept after playing this game scored significantly higher on a retest than those who did not sleep. While asleep they apparently figured out what they didn’t while awake: the structure of the simple hierarchy that linked the pairs, paisley over aqua over rainbow, and so on. “We think what’s happening during sleep is that you open the aperture of memory and are able to see this bigger picture,” said the study’s senior author, Matthew Walker, a neuroscientist who is now at the University of California, Berkeley. He added that many such insights occurred “only when you enter this wonder-world of sleep.” Copyright 2007 The New York Times Company

Keyword: Sleep; Learning & Memory
Link ID: 10873 - Posted: 06.24.2010

By GINA KOLATA As every sleep researcher knows, the surest way to hear complaints about sleep is to ask the elderly. “Older people complain more about their sleep; they just do,” said Dr. Michael Vitiello, a sleep researcher who is a professor of psychiatry and behavioral sciences at the University of Washington. And for years, sleep scientists thought they knew what was going on: sleep starts to deteriorate in late middle age and steadily erodes from then on. It seemed so obvious that few thought to question the prevailing wisdom. Now, though, new research is leading many to change their minds. To researchers’ great surprise, it turns out that sleep does not change much from age 60 on. And poor sleep, it turns out, is not because of aging itself, but mostly because of illnesses or the medications used to treat them. “The more disorders older adults have, the worse they sleep,” said Sonia Ancoli-Israel, a professor of psychiatry and a sleep researcher at the University of California, San Diego. “If you look at older adults who are very healthy, they rarely have sleep problems.” Copyright 2007 The New York Times Company

Keyword: Sleep
Link ID: 10872 - Posted: 06.24.2010

By Scott McCredie The photograph, even today, arrests the eye and titillates the mind. It's from the early 20th century, and the young man it shows -- tipping back on the rear legs of his chair -- is using his own legs, splayed in front of him, as a counterbalance. The feat itself isn't that impressive. It's his location, perched high over a cityscape of tall buildings. A wobble would be fatal. What strikes me most about the photo is what it suggests about the extraordinary adaptability of our sense of balance. Here's what I mean: Suppose the photographer grabbed a guy off the street and forced him to change places with the unnamed acrobat in the chair. The results would be predictable: Without a safety net, the new guy would almost certainly fall to his death. That's because his balance system wouldn't have had time to adjust to the specific demands of balancing on two legs of a chair while perched on the edge of a tall building. But if that guy off the street had gone through the same training as the acrobat, chances are he might well eventually become adroit enough to perform the trick. © 2007 The Washington Post Company

Keyword: Miscellaneous
Link ID: 10871 - Posted: 06.24.2010

By Sharon Jayson, You might have guessed it, but now researchers have real proof: Sleep deprivation causes our emotions to go haywire. That's according to the first neurological probe into the emotional brain without sleep. It was carried out by researchers at the University of California-Berkeley and Harvard Medical School. "Most people think that when you're sleep-deprived, what happens to the brain is that it becomes sleepy and less active," says Matthew Walker, assistant professor of psychology at Berkeley and a former Harvard sleep researcher. But Walker says the imaging study published in today's issue of Current Biology found that the brain's emotional centers become "60% more reactive." The study also suggests that lack of sleep elevates activity in the emotional centers of the brain most closely associated with psychiatric disorders such as depression. Walker's team studied 26 people ages 18 to 30 who were divided into two groups. The sleep-deprived group was awake 35 hours; the other group slept normally. Using the brain scans, the researchers showed participants a series of images, from neutral to increasingly negative and disturbing. The responses of both groups showed up as hot spots, but the sleep-deprived evoked stronger responses because the prefrontal area of the brain that normally sends out inhibiting signals wasn't able to keep emotions in check. Copyright 2007 USA TODAY

Keyword: Sleep; Emotions
Link ID: 10870 - Posted: 10.23.2007

The young mice in Clinton Rubin's lab don't look like they're exercising; they're just nosing around a plastic tub looking either for something to eat or a way out. But, these mice will grow up leaner than a similar group of mice elsewhere in the lab. The difference is that these mice are spending 15 minutes a day for 15 weeks being vibrated ever so slightly in a tub that rests on a platform that looks like a giant pizza box attached to electronics. The vibrations are very slight, so slight many people can't feel the vibration, only hear the hum. In tests at his lab at Stony Brook University lab, Rubin and his team showed that after the vibration regimen, the mice had 28 percent less fat in their torsos than another group of the same kind of mice who ate the same amount of food, and had the same amount of exercise. Writing in the Proceedings of the National Academy of Sciences, Rubin explained that the vibrations, "also reduced key risk factors in the onset of type II diabetes." Rubin explains that his interest is in how physical signals – outside influences of mechanical, electrical and thermal signals – can influence the body. While his research has centered on bones, that work has taken a temporary detour into fat because both bone cells and fat cells, along with muscle, come from the same stem cells. Stem cells are special cells the body generates that can then turn into other cells as the body needs them. © ScienCentral, 2000-2007.

Keyword: Obesity
Link ID: 10869 - Posted: 06.24.2010

Results of a new study may one day help scientists learn how to enhance a naturally occurring mechanism in the brain that promotes resilience to psychological stress. Researchers funded by the National Institutes of Health's National Institute of Mental Health (NIMH) found that, in a mouse model, the ability to adapt to stress is driven by a distinctly different molecular mechanism than is the tendency to be overwhelmed by stress. The researchers mapped out the mechanisms — components of which also are present in the human brain — that govern both kinds of responses. In humans, stress can play a major role in the development of several mental illnesses, including post-traumatic stress disorder and depression. A key question in mental health research is: Why are some people resilient to stress, while others are not? This research indicates that resistance is not simply a passive absence of vulnerability mechanisms, as was previously thought; it is a biologically active process that results in specific adaptations in the brain's response to stress. Vulnerability was measured through behaviors such as social withdrawal after stress was induced in mice by putting them in cages with bigger, more aggressive mice. Even a month after the encounter, some mice were still avoiding social interactions with other mice — an indication that stress had overwhelmed them — but most adapted and continued to interact, giving researchers the opportunity to examine the biological underpinnings of the protective adaptations.

Keyword: Stress
Link ID: 10868 - Posted: 06.24.2010

The power of the mind has been overestimated when it comes to fighting cancer, US scientists say. They said they found that a patient's positive or negative emotional state had no direct bearing on cancer survival or disease progression. The University of Pennsylvania team followed more than 1,000 patients with head and neck cancer. But experts said the Cancer journal study should not deter people from adopting a "fighting spirit". Indeed, a positive outlook can help patients cope with gruelling cancer therapies and resume a "normal" life, a spokeswoman for Macmillan Cancer Support said. Seeking emotional support may be beneficial to cancer patients, said the researchers. Lead author Dr James Coyne said: "If cancer patients want psychotherapy or to be in a support group, they should be given the opportunity. There can be lots of emotional and social benefits. But they should not seek such experiences solely on the expectation that they are extending their lives. The hope that we can fight cancer by influencing emotional states appears to have been misplaced." In the study, a patient's emotional status had no bearing on survival, regardless of gender, tumour site or disease stage. Julia Frater, of Cancer Research UK, said: "People with cancer can feel under pressure to cope well with their disease and treatment and to stay on top of things. They are often urged to feel positive. "These results should reassure them that if they don't feel like this, it's okay. Many people do feel worried or low following a diagnosis and this isn't likely to affect the outcome of their treatment." (C)BBC

Keyword: Neuroimmunology; Emotions
Link ID: 10867 - Posted: 10.22.2007

By Fergus Walsh A gene therapy trial for the fatal disorder Duchenne muscular dystrophy (DMD) is about to begin in London. In a world first, a small group of patients will be injected with an experimental drug which it is hoped will extend their lives. DMD, which affects boys, is caused by a single faulty gene, and results in progressive muscle wasting. The injection contains a "molecular patch" targeting the faulty gene so that it should work again. At first, minute quantities of the drug will be used - to check it is safe. If it works the drug will effectively knit together the key damaged section of DNA, allowing it to begin producing a protein that keeps the muscles strong. The hope is it could slow, or even halt the progression of muscle wasting, and give some patients the chance of living into old age. Animal trials of the drug have proved highly successful. If it works in humans, patients would need regular infusions of the drug. Lead researcher Professor Francesco Muntoni, of Imperial College London, has high hopes. He said: "It will be truly life changing, and life extending for these people. "Maybe this will not be a complete cure, but it could definitely buy a lot of time for these children." Professor Muntoni describes the gene therapy as like a piece of molecular velcro which will form a temporary repair. (C)BBC

Keyword: Muscles; Genes & Behavior
Link ID: 10866 - Posted: 10.22.2007

Donald Wilson In 2004 the Nobel Prize in Physiology or Medicine went to Linda B. Buck and Richard Axel for their research showing that there is a huge family of genes that encode proteins called olfactory receptors. Their findings, published in 1991, opened many doors toward understanding the function of the olfactory system. One important observation was that individual olfactory sensory neurons typically express just one of those genes. Thus, signals coming from a given neuron provide information about odors that activate the specific receptor protein expressed by that cell. A single receptor protein, however, appears to bind (or recognize) many different odors. Thus, rather than having neurons that respond selectively to coffee or vanilla or Bordeaux, most individual cells (via their receptors) respond to submolecular features of the volatile chemicals coming from those objects. For example, an olfactory sensory receptor neuron may respond to a hydrocarbon chain of a particular length or a specific functional group like an alcohol or aldehyde. This means that any given sensory neuron will respond to many different odors as long as they share a common feature. The brain (specifically, the olfactory bulb and olfactory cortex) then looks at the combination of sensory neurons activated at any given time and interprets that pattern in the context of previous patterns that have been experienced and other kinds of available information. The interpreted pattern is what you perceive as smell. Olfactory sensory neurons, which sit in the mucus in the back of the nose and relay data into the brain via axons (fingerlike projections that transmit information out from the cell body), do not live forever. In fact, they are one of the increasingly large number of neuron types that are known to die and be replaced throughout life. © 1996-2007 Scientific American, Inc.

Keyword: Chemical Senses (Smell & Taste); Neurogenesis
Link ID: 10865 - Posted: 06.24.2010

By JASCHA HOFFMAN Has the Clean Air Act done more to fight crime than any other policy in American history? That is the claim of a new environmental theory of criminal behavior. In the early 1990s, a surge in the number of teenagers threatened a crime wave of unprecedented proportions. But to the surprise of some experts, crime fell steadily instead. Many explanations have been offered in hindsight, including economic growth, the expansion of police forces, the rise of prison populations and the end of the crack epidemic. But no one knows exactly why crime declined so steeply. The answer, according to Jessica Wolpaw Reyes, an economist at Amherst College, lies in the cleanup of a toxic chemical that affected nearly everyone in the United States for most of the last century. After moving out of an old townhouse in Boston when her first child was born in 2000, Reyes started looking into the effects of lead poisoning. She learned that even low levels of lead can cause brain damage that makes children less intelligent and, in some cases, more impulsive and aggressive. She also discovered that the main source of lead in the air and water had not been paint but rather leaded gasoline — until it was phased out in the 1970s and ’80s by the Clean Air Act, which took blood levels of lead for all Americans down to a fraction of what they had been. “Putting the two together,” she says, “it seemed that this big change in people’s exposure to lead might have led to some big changes in behavior.” Copyright 2007 The New York Times Company

Keyword: Neurotoxins; Aggression
Link ID: 10864 - Posted: 06.24.2010

Rex Dalton Fossils can shed light on when bats developed the ability to echo-locate.GETTYThe most primitive bat ever discovered is finally being scientifically reported, years after the first fossil was found and snapped up by a private collector. The 52.5-million-year-old bat unusually had a claw on all five digits of each limb, earning it the nickname '20-clawed bat'. Its anatomy shows that it captured its prey without the use of echolocation — the strongest evidence yet that some bats flew before this skill evolved. Bats are thought to have evolved from flightless tree-dwelling creatures, and also developed specialized echolocation to detect their small prey at night. Which came first has been a matter of some debate. “This tells us there was flight before echolocation,” says Nancy Simmons, the chief mammal curator at the American Museum of Natural History in New York. “So the question we have to answer now is: how did it catch its prey?” Simmons and her colleagues reported on two individual fossils of the new bat late last week in a lecture at the 67th annual meeting of the Society of Vertebrate Paleontology (SVP) in Austin, Texas. The team has submitted an article naming and fully describing the species to a scientific journal. Bats today make up about 20% of living mammals. There are an estimated 1,100 species, with new ones reported regularly. The previous oldest bat found is from the same place and age as the new species, but the new find has more primitive features. © 2007 Nature Publishing Group

Keyword: Hearing; Evolution
Link ID: 10863 - Posted: 06.24.2010